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<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<title></title>
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<body>
	<script type="text/javascript">
		// 1. 求半径为r的圆的面积和周长(r是参数)
		// Π Math.PI表示Π值
		function area(r) {
			let s = Math.PI * r * r
			let l = 2 * Math.PI * r
			// \转义字符 \n换行 \t空格
    		return "面积是" + s + "\n周长是\t" + l
			}
			console.log(area(4))

			// 编写一个函数，计算任意两数字之间能组成的所有奇数0--3》01 03 11 13 21 23

			let a = ""
			function fn(start, end){
				for(let i = start; i <= end; i++){
					// 找出个位数 个位数是奇数整体是奇数
					if(i % 2 == 1){
						for(let j = start; j <= end; j++){
							// a = a + "" 
							a += '' + j + i + " "
						}

					}
				}
				return a
			}
			console.log(fn(0,9))

	</script>
</body>
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